We live on the Oregon coast & started asparagus from seed in a green house. We up potted them to 4\" pots & they are now aprox. 12\" tall. The question is do we trim the ferns back & leave them in the pots to over winter in the green house or is there a better way. They are very healthy plants. Thanks in advance.
You could leave in the greenhouse and plant out in spring. They need to have a cold period and you should add extra insulation around them.
Make sure they do not completely dry out.